Telephone system



G. GRABE.

TELEPHDNE SYSTEM. APPLICATION FILED JAN. 14. 1915. RENEWED NOV. 8. ms,

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G. GRABE.

TELEPHONE SYSTEM. I APPLICATION FILED JAN. 14, 1915. RENEWED NOV. 6. 1919.

- 1,343,714. Patentedlune 15,1920.

0 3 $HE.ETSSHEET 2- 121.5 always (i. GRABE.

TELEPHONE SYSTEM. APPUCA'HON FILFD JANQM, I915- RENEWED NOV-6.1919.

1,343,714. Patented June 15, 19 20.

3 SHEETS-SHEET 3- 215 Jlzarneys UNITED snares,

enraur QFFWEE.

GEORG GRABE, 0F NIKOLASSEE, NEAR BERLIN, GERMANY, ASSIGNOR TO SIXTEENS HALSKE, A. G., OF BERLIN, GERMANY, A CORPORATION OF GERMANY.

TELEPHONE sYsrnM,

Specification of Letters Patent.

Patented June 15,1920.

Application filed January 14, 1915, Serial No. 2,233. Renewed November 6, 1919. Serial No. 336,232.

To all whom it may concern:

Be it known that I, Gnono GnAnn, a citizen of the German Empire, and residing at Nikolassee, near Berlin, Germany, have invented certain new and useful Improvements in Telephone Systems, of which the following is a specification.

This invention relates to automatic or semiautomatic telephone exchange systems and particularly to exchanges operated by selecting switches connected to a plurality of groups of trunk lines and set by means of a continuous actuating driving force operable in only one direction.

The primary object of the invention is to provide an improved organization of circuits and apparatus by which the selective connection of two subscribers instruments may be accomplished more rapidly and with greater certainty, than heretofore.

An other object of the invention is to adapt such selecting switches to be operated by means of number impulses and to attain a higli speed for the setting operation of such switches.

For this purpose the selecting switches are started by a driving mechanism which is controlled by number impulses generated in an impulse circuit, whereas the movement of the switches is stopped by another preferably a testing circuit.

ln the drawings, Figures 1 and 2 show a circuit diagram illustrative of the mode of operation of the exchange.

Fig. 3 is a detail View ot' an escapement mechanism used in connection with the driving mechanism (not shown) of the connector switches.

Fig. 4 is a side elevation of a driving mechanism adapted for use in connection with selector switches or connector switches, the escapement shown in this figure being for a selector switch.

For the sake of clearness only such portions of the circuits and apparatus have been illustrated as are requisite for understanding the invention.

It is deemed advisable to proceed with a -'les :ription ot' the circuits and mode of operation of the system, whereas details of mechanism will be des'ribed later.

The circuits are illustrated by Figs. 1 and 2, e n X diagrammati ally repre ents a calling station, VVV a line switch, GlV a selector and LlV a connector.

The operation of the system is as follows:

When the subscriber at the calling station N takes off the receiver, the following circuit is closed: ground, battery, first eXciting coil, of the call relay Ra, contact it, subscribers line (1., contact 2', receiver hook, subseribers line 7), contact 225, second exciting coil of the call relay Pia, ground. In this circuit the call relay Ra is energized causing the wipers of the line switch VlV to advance to idle terminals of a selector GlV. As soon as the wipers of the line switch V'W engage idle terminals oi a selector GW a current is caused to flow from ground through battery, contact 3m which is closed by the'relay Ra, relay T, trunk line 1, normal contact 701 to ground. The relay T which is energized in the said circuitwill detach at the contacts 1t, 2t the relay Ru from the subscribers lines a, Z) and extend the connection to the trunk lines (11, 61. The conta(t 42? which is closed by the relay T will short circuit the high resistance winding of the relay T and, at the same time, maintain the other winding of the relay T excited. Thus, the engaged trunk line of the selector GlV will be locked against seizure. The connection being extended to the trunk lines (61, 711 the relays A, B are energized in a circuit over contacts 56, 66, whereas the relay X in this circuit being a differentially wound relay will remain dei nergized.

It now at the subscriber station N the dial Fe is turned in the direction of the arrow, the contact ck is closed. Thus, th subscribers lines (1., 7) of the talking conti \ction are simultaneously grounded. The di 'erentially wound relay X will become excited thereby and close its contact .1", so that the relays A, B remain energized. The dial Fe having been set and released, the niimber impulses are generated by correspondingly making and breaking the contact At each interruption ot' the current at contact 2' the relay A of the selector (V is momentarily deenergized whereas the relays B and X remain excited. As soon as the selector (.irW leaves its normal position the normal contact k1 is opened and the contact 771 closed by the relay B. This relay also'closes the (ontacts 8K) and 9!), whereby on the one hand, the

amljart A2, contact lay lil normal .i. .LVWJA l i also QJLHGB inc "ounil. he rela) contact ll and ihcn opens ilhc back (911* "aac; 'lEcc.

terminals oi the selector (lil are engage the wipers oi the line SWli-(fill Vii", tho relay-x; Ii. ind ll heroine simultaneously energized and tho contacts 8!, and i011 clogseih so that the l'clays R and 3 ll siinultancously respond to the exciring current, At this operation the wipers a, 5 (a (i remain in {heir normal position 0. as ihc relay K hcco'mes excited the hack contact 13.2 is opened and the working contact 9,0, l lrlr clisciih whereby he i pcrai'iion of "the relay heroines dependent upon vthe position ol thc conlacts 1015 and lZu. The wipers a, Z (i, (Z, however, leave illOli normal position only at the time the number impulses are sent out.

We will suppose that the suhscriher at thc station N has sent out 021i} a single impulse as the first of a series of nuinher impulses. Thus, the relay A l will he once deiinergizcd, 3;) he hacic contact 121/, closed and thereafter the working; contact ll, opencdl fit the same time the contact llm will he opened and the current through thci 1 7 ca will cease so that the wiperss a, I), c, (i will he moved 55 from their normal pUSlii'iOEl (J (o the con- 'tzictg; ()0. V l? the hack coinarf 12a is closed the wipers (1 o. in; engaging the contact 0 will after a short stop he moved to the (()Iltacls (ll); should howeveiu at the time fihe back contact 12a lit open said wipers will he moved a l once to (he contacts (Hi0. ln this position the relay ll will lie reiincrgizcd ovcr the workin; contac'c 71a: and the. wipers remain in their position until the relay A will. become excii'ed again. ls soon as the wipers more out of their normal position (l the normal contacts firl, Z72 will he opcncd and ihc contact k3 be cloSed. lly the: opcning of the contact the influence of the contaci, 10a on the relay 2 3 will cease" ll'hen now the relay A is again cnergzized, the circuii; through the relay S will be broken at the working contact 11a. The wipers will then be moved a further step anal-an idlc trunk line be selcctcd from tlic first group of contacts which are connected with trunk lines liading to ofhcr selectors. The testing is accomplisihed by the relay 5% in such a manner that, ilihe i dial Fa returns to its normal position, She (s0 relay will become dciinergi 1' whereby the testing c'rcuit of the rclay over the testing wiper will he closed at the back contact 13.11. The relay 5% l.)i;i. P-.1L fBIlGlglZGLl as soon the wiper Gilfl'iU-GS 5.5 of an idle trunk line a may trunk line As soon extended over coi'ihictg-i liar 19s to the "We will suppose ch-st terminal r. r A rill L allow oi an coeig ll" ti incc the reli I s cnc l lector i aco ml included in the circuili.

ll'hcn the wipers; a, (3 c v uals oi rho trunk lines 650 l of the .sclector (i i and in the relay (f at thc follow energizech ihc currcnt l'lowir through hatter relay H cool ing: relay ll, contact 9!) wipe (2, contact, ls'mi, relay 5.. ground. i

Tho relay 1 "vil contact 171, and include the i. in the circuit thus locking like against seizure. The rclay S wl e11 gizcd will attract its armatur and wipers of the scicctoron the line. The talking con tion will Link lincs (12- 152. iuliancously with he relay S the relay la is energized which. zachcs the relays A B, I; from the talking lino opening the contacts 5c, 6c. The elay closes the coi'itactflllc and eiitablisl i circa i, for the relays bl, E and U independently of thc contact 97 which will he opencil soon as the relay ll is detached from the talliin line by breaking theuconiact (3c. The rcla 5 closes the contact 21. and estahlishcs Elli" 35 other circuit for the relay T of rho line switch Viv,

li', however for setting he sclccior G? a plurality of number impulses in Scri instance two are scni ou: by the. :allin lion N rile wi ers a, I, (a oi the 3Ci1i21 are moved aflcr tho firs; impulse bu w tarts ll after the second impulse #0 iii tarts If" 71"". W, W" and so on wire u automatic selection of an idle terminal taires 'io placev in tho desired group trunk lines ihe selector of for Sean (lil two impulses have been sent out. already explained, tho wipers a I), r; rcach the contacts 000, if after The first impulse il the relay A is again reenergizcdi Before, however, the relay 1 is dcencrgixed and the wipers are automatically ogeraled thereby.

the relay A is temporarily deenergized and reencrg'ized for the second impu 5c. 'l' ii this time the relay A. is deiinergizcd ihc circuit over the working co'i rac'r or; is broken at the hacli contact 120. lhc relay i therefore, releases its armature, and the wiperh' are turned a further step. If tho wip i reach the contacts a F)", c a before; the hack contact 124 is hrokcin they remain in the position until the contact 1.12 is op I). whereupon they are moved to the contacts a 11, 0" (Z. #:lhould, however the hack contact 12a be broken when the Wipers engage the contacts in F1 0", (Z rho wipers will at once he curried E0 the contacts ri li fl cf Z"". If then the relay ll. is a ain energized and the working contact lilo closed. the aui' io niatic selection 01" an idle terminal in the second group of trunk lines at the selector Gi /Y takes place. For this purpose the relay 6 is cut into the testing circuit over the back contact 1.3.0 by breaking the contact c/.; at the subscribers station Ii when the dial returns to its normal position so that the relay X is deenergized before the back contact 12a, is broken by the reenergization of the relay A.

If after conversation the connection is released the contact 15m at the selector subsequent to the selec or (ill' will be opened and. the circuit for he relays U, E and :5 broken. 'llhe relay it being slow acting will release its armature only after the selector til has reached its normal position of rest 0. The selector (tli' is moved into this position as soon as the relay 2% becomes eleenergized, so that its armature is released. The rotary movement of the selector GW continues until the arrmatui'e oi the electromagnet It is released. This operatlbn takes place if the wiper c engages the contact 0, the contact #3 as well as the circuit through the electromagnet ll being broken at the same time.

In order to prevent a rotation of the selector (PW to the succeeding group oi terminals. it all terminals in a tested group are busy, additional contacts ul, 6"", c el are provided between two succeeding groups of tcrn'iinals. it all terminals'in a group preceding said additional contacts are busy, the wipers stop at the said additional "contacts. If, for instance. the wiper c engages theaddit-ional contact c", the following circuit is established through the relay h: ground battery, relay h, back contact 13 1: o'l relay X relay I). working contact 9/), wiper c, contact 0"". resistance 1.02 to ground.

lletcrring now to Fig. 2 the operation (it the connector is as follows:

if the lixed terminals of the connector Ill V are engaged by the movable terminals of a selector til the relay A bridged across the talking lines will be energized. The contact 3301/." is now closed and the relay V1 which is slow acting will be energized so that the contact 3112i is closed andthe eiectronulgnet excited. lly this operation the lock of the armature ot the relays to" and l is released (Fig. 3). Said armature can. however. not be moved since the relay Fliifl simultaneously excited with the relay l t. the circuitcxtending from ground over contact 320, normal contact M3. lirst exciting coiloit the relay H. normal contact #7. battery. to ground. It now the first series ot' number impulses tor setting the connector lfW is sent out-and which series may be supposed to consist of two impulscsthe wipers (1*. 71*. c are moved in the. same manner as already described with reference to Fig. 1 until after the second impulse they engage the contacts u*"". 72?", d This setting of the wipers being accomplished by deenergizing anti and reenergizing the impulse relay A operating the contacts lie and 1:5 controlled by the relay A" in a similar n'ianner. as the contacts llo and 12a of Fig. l -While the impulses are being sent out the relay V2. 7 is energized by a circuit from ground through battery over contact p, relay V2, contacts 34ml, 33a" to ground, and holds its armature attracted which will. be released. only after sometime is elapsed ai'ter the last impulse of the series. Since the relay V2? is slow acting the contact 3502 will be broke 9 so that an energization of the relay U rented. If after completion of the series of number impulses the relay A beconies e1;- cited for a longer period and the armature of the relay V2 is released, this relay Wll'lr'SlU'eQ its contact as U1 and excite the relay ll. The relay i by closing its contact 36o remains excited independently of the condition or the relays Y2 and A.

lVhen the second series of number impulses is being sent out and the relay Bl cleenergized, the relay Y2 becomes again excited and holds its armature attracted until the semling out of the number impulses is completed. Since. however. during this operation the relay l isenergizcd a circuit the relay F and the second exciting coil ll of the relay S is established over the contacts Sin." and 391/. The exciting coil l of the relay 3. which is dili'erentially wound to the exciting coil II. will be energized as soon as the relay l is excited and the. contacts 3911/. 40c] and i-l'rl are closed. This exciting coil 1 oi the relay 5% remains energized until the connectorl1 is released. it the second series of number impulses is sent out and the relay is dei nergizcd the exciting coil ll oi the relay 5" as well as the relay l will become excited over the closed contact 37/1 The diftcrent-ial relay H will now release its armature so that this armature may be atti acted by the relay l (sce'l ig. 3) and the wipers of the connector may be moved halt the way from contacts (1 F c (F to the next succeeding contactsfl 'lhese latter contacts will be re. died by the Wipers soon as the relay A is reenergixed. the circuit through the exciting coil ll ol the relay EV and the relay I being broken again at niact 37/! so that the armature may be again. attracted by the relay l in the same mare nor the wipers are moredby ea h impulse to the next contact so that tor instaiuc by l'" number impulses the wipers will be iiio'i the terminals of the lines (/3. b3 oi subscriber. .\l'tcr haying sent on number impulsithe relay Y2 will armature still attracted tor a cer During this period the conncc called subscriber will be tested. l t the lei minal of the line to the called subs riber is idle a circuit will be established extending from groinid throughbattery. both. coils the contacts 52 and. 53p of the e .2

.ilms ti will. broken anal thereby The excited relay L will clos. .30 and 51 and apply ringing f ce led subscribers lines a3 t3.

'vl' hen the called subs 'bei' till- PS oil" ieceii' er e relay Y becomes e: This 1" will open contact thus one t e L the singing SUILTQL the talking; cor iectioo i8 '11 Should the collie/cl suhsc ll not he the ne switch i l l is position and, therefore, he 11 n .0 met 45731 broken, if in the estsl'ilishec COnlflQCilOll theseicl subscriber was the calling subscriber. If, however, the subscriber had been called. the relay P will not get sullicient energy, since the test relay oil the connector is shortcircuited v If after conversation the established COH- nection is released by replacing the receiver at the willing station N the relay A as as the fehiy V1 will become (leene e contacts closed by the relay V1 the relays U 5 The relay ll hoivever,

3 10M. since busy the relay w and. (le'energizecl. remains still excited. for it short 1 the normal contact ME is closed. AL: the armature of the relay S is released the Wipers of the connector L'W Will. be rotated until they reach their norn'iel position "'0 in which the circuit for the relay it is broken at the normal Contact Z242 Fig; 4 shows in detail. the driving mechanism adapted for use in connection with selector switches 01" connector switches; The escepement illustrated in this figure is con structed for a selector switch:

011 the shaft 61 is loosely mounted e ratchet 'Wl166l62 which is rigidly connected with a (lrum 63. ill. coiledspring is connectecl at its one end 64k With the drum (53 and. With its other end at 65 with the shaft 63. or With a clisk 66 mounted on the Cn the drum 63 is provided a closecl contact ring 6'? which is insulated irom the drum and engaged by :1 contact brush :ontact ing 67 is provided with another contact brush 69 which engages another con 1 gloups, a switch, a ili'iviiig iii snism there lotiz an impulse circuit i 21:1 the no ector 'Wip acts which the esce Jement 86 so I t the d1 vino me will. cause A the gezirin T2, 82 (L sl'e by step mo ement of the selector W /ears 8;. mover! exit coileflwsp .n p 'tleel in the (lium 6 55 wi l be partl T3301 sion that a the CODltC-l contact s 4 brush contact s 1 ratchet liet w; l (32 so be Wouml 1% circuit oken. 'llie intcl'iup quickly hat the selector is col.

able.

The selector may also be oywrateclivithout the gearing 7.2 82, slim 13.. this case the MC: selector Wipers will he provided on the shaft 61 and the gear whee Y2 formed. an escape meet Wheel.

telephone exchange system, comprisi253 bllli'lk lines ziri'zi a plurality of "I i s oesi'ree group of circuit 1 5 by means of said driving mechanism, a testing circuit to stop said movement once for each movement in said impulse circuit, and special contacts located between the contacts ofsaid groups of contacts for closing said testin circuit.

K telephone exchange system, comprising trunk lines arranged in a plurality of groups, each group comprising a plurality of trunk lines, a switch, driving mechanism therefor, an impulse circuit to set said switch on a desired group, said impulse circuit starting the movement of said switch by means of said driving mechanism, another circuit to stop said movement and athird circuit causing said switch to select an unoccupied trunk line out of said plurality of trunk lines of'said desired group. i

4. A telephone exchange system comprising trunk lines arranged in a plurality of groups, each group comprising a plurality of trunk lines, a switch, a driving mechanism therefor, an impulse circuit to set said switch on a desired group, said impulse circuit starting the movement of said switch by means of said driving mechanism, a second circuit to stop said movement, a third circuit causing said switch to select an unoccupied trunk line out of said plurality of trunk lines in said desired group, and means to, prevent said switch to select an unoccupied trunk line in a diiferent group of trunk lines, when all trunk lines of said desired group are occupied.

5'. A telephone exchange system, comprising trunk lines arranged in a plurality of groups, a switch, a driving mechanism therer for, an impulse circuit to set a switch on a desired group, said impulse circuit starting the movement of said switch by means of said driving mechanism, a second circuit to stop said movement once for each movement in said impulse circuit, and means to 1 re-arrange said circuits to receive a second series of impulses in said impulse circuit to particular line in said desired group.

6. A telephone exchange system, comprising trunk lines arranged in a plurality of groups, aswitch, a spring actuated driving mechanism therefor, meansto restore the tension of said spring, when reduced by the movement of said switch, an impulse circuit to set said switch on a desired group, said impulse, circuit starting. the movement of said switchby ineans of said driving mechanism, and another circuit to stop said movement.

7. A telephone exchange system, comprising trunk lines arranged in a plurality of groups, a switch, spring actuated driving mechanism therefor, an impulse'cir'cuit to set said switch on a desired group, said impulse circuitstarting the movement of said switch by means of said driving mechanism, a testing circuit to stop said movement of said switch, and electromagnetically I operated means to restore the tension of said spring,

and circuits to start and 'stop'said restoring means.

8. A telephone exchange system, comprising trunk lines arranged in a plurality of groups, a switch, spring actuated driving mechanism therefor, an 'impulseggeircuit to set said switch on a desired group, said im- I pulse circuit starting the movement of said switch by means of said driving mechanism,-

a testing circuit to stop sai'd movements, electromagnetically operated means to restore the tension of said spring, circuits to start and stop sald restoring means, said circuits starting said restoring means withjthe beginning of the movement of said switch and said circuit stopping said restoring means when the tension of said spring is restored.

passing through said solenoid, one end ofsaid core being attached to the ratchet of said restoring means, the other end being attached to a spring controlling the extent of the movement of said core.

'10. A telephone exchange system, comprising a switch, a spring actuated escapement wheel therefor, an oscillatory escapement,

circuits to start and stop the movements of said escapement, electromagnetically oper- 9. A telephone exchange system, compri's' ing trunk llnes arranged in a plurality of.

ated means to restore the tension of said spring, comprising a solenoid and an oscillatory core for drivingsaid restoring means, said escapement and restoring means being independent from each other.

In testimony whereof, I have signed my name tothis specification in the presence of two witnesses.

.GEORG GRABE. Witnesses:

WOLDEMAR HAUPT,. HENRY HASPER.- 

